html,
body {
  margin: 0;
  height: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
}

html {
  background-color: #fff;
}

button {
  padding: 5px 16px;
  border-radius: 8px;
  line-height: 1.4;
  cursor: pointer;
  transition: 0.3s;
  transform: scale(1);
  border-color: transparent;
  background-color: royalblue;
  text-shadow: 0 -1px 0 rgba(0, 0, 0, 0.2);
  box-shadow: 0 2px rgba(0, 0, 0, 0.0431372549);
  color: #fff;
}
button:hover {
  filter: brightness(1.1);
}
button:active {
  transform: scale(0.95);
}

.list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 15px;
  margin-top: 20px;
}
.list .item {
  width: 200px;
  height: 150px;
  background-color: royalblue;
  border-radius: 10px;
}